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RAC Servicing (DomRAC) NC II study materials
RAC Servicing (DomRAC) NC II study resources

RAC Servicing (DomRAC) NC II practice questions

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Question 1Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician must report a refrigerant leak found during a routine PM visit at a client's residence. Which communication approach best fits workplace standards for a domestic refrigeration and air-conditioning servicer?

  1. Send the details only to a co-worker so the office learns about it later
  2. Inform the homeowner verbally and record the finding, action taken, and parts needed in the service report Correct answer.
  3. Wait until the next scheduled visit before mentioning the leak to anyone
  4. Post the finding on a public social media page to reach the client faster

Explanation

Service documentation is the standard channel for reporting findings to the client and the office, and it keeps a record of the leak, the corrective action, and the parts required. Verbal notice alone is weak, and informal channels such as social media or relayed messages do not create a defensible record.

Question 2Basic Competencies (workplace communication, teamwork, safety, quality standards)

In a DomRAC shop, which practice shows correct use of the communication equipment commonly issued to field technicians?

  1. Leaving the radio in the van while working on a rooftop unit
  2. Keeping the two-way radio on the assigned channel and confirming receipt of instructions Correct answer.
  3. Switching the radio to any channel that sounds clearest at the moment
  4. Using the radio to pass personal messages during peak service hours

Explanation

Assigned-channel discipline with acknowledgment of instructions keeps coordination reliable and prevents missed or duplicated work orders. Wandering channels interfere with other crews, and leaving the radio behind breaks contact during lone work.

Question 3Basic Competencies (workplace communication, teamwork, safety, quality standards)

A supervisor gives a technician a work order written in a language the technician reads slowly. What is the most appropriate workplace response?

  1. Sign the order as read and proceed to the next task
  2. Ask the supervisor to clarify the key instructions and confirm understanding before starting Correct answer.
  3. Ask a co-worker to do the job instead without informing the supervisor
  4. Begin the job and interpret the order as best as possible without asking

Explanation

Confirming understanding of instructions before work starts prevents errors and is a normal part of receiving a work order. Guessing at the content or silently passing the job to someone else leaves the task unaccounted for and hides a communication gap.

Question 4Basic Competencies (workplace communication, teamwork, safety, quality standards)

During a team briefing before a split-type installation, which behavior best demonstrates effective teamwork?

  1. Starting the mounting work independently while others are still being briefed
  2. Confirming each member's assigned task and the sequence of work before starting Correct answer.
  3. Assigning tasks to teammates without the supervisor's knowledge
  4. Discussing a teammate's mistake from a previous job in front of the client

Explanation

A short confirmation of roles and work sequence prevents duplicated effort and gaps during installation. Self-assigned task changes and public criticism of teammates undermine coordination and trust.

Question 5Basic Competencies (workplace communication, teamwork, safety, quality standards)

Which item is the first thing a DomRAC technician should confirm before starting any service call at a client's home?

  1. The price of refrigerant at the nearest supplier
  2. The color of the client's unit casing
  3. The scope of work and the safety hazards identified for that site Correct answer.
  4. The brand of tools carried in the service bag

Explanation

Scope and identified hazards determine what work is authorized and which controls are needed, such as lockout, ventilation, or fall protection. Cosmetic and supply details do not affect readiness for the task.

Question 6Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician notices that a recovered refrigerant cylinder in the shop is unlabeled. What is the correct action under good workplace practice?

  1. Release the contents to atmosphere to empty the cylinder
  2. Set it aside, tag it as unidentified, and report it to the supervisor before any transfer Correct answer.
  3. Store it with labeled cylinders so it can be identified later
  4. Use it for the next charging job to avoid waste

Explanation

Unlabeled refrigerant cannot be safely identified, so it must be segregated, tagged, and reported rather than used or released. Mixing unidentified refrigerant with known stock risks contamination and unsafe charging.

Question 7Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician is asked to work alone on an outdoor condensing unit on a wet roof. Which combination best reflects the required safety judgment?

  1. Proceed quickly so the exposure time on the roof is shorter
  2. Assess the slip hazard, use fall protection where required, and postpone if conditions are unsafe Correct answer.
  3. Ask the client to hold the ladder while the technician works on the roof
  4. Work without fall protection because the job is short

Explanation

Lone work on a wet elevated surface requires hazard assessment and the specified fall protection, and the task should be deferred if controls cannot be met. Speed or improvisation does not replace the required control measures.

Question 8Basic Competencies (workplace communication, teamwork, safety, quality standards)

During a team job, a junior technician is unsure how to braze a joint safely. What is the best teamwork response from the senior technician?

  1. Demonstrate the correct procedure and supervise while the junior performs it Correct answer.
  2. Perform the task silently so the schedule is not delayed
  3. Tell the junior to practice alone and report the result later
  4. Instruct the junior to skip the brazing step

Explanation

Coaching with demonstration and supervised practice transfers the skill while keeping the work safe and within standard. Leaving an unsure worker unsupervised or skipping a required step compromises both safety and quality.

Question 9Basic Competencies (workplace communication, teamwork, safety, quality standards)

A client complains that the unit still does not cool after a repair. Which response best follows good workplace communication and quality standards?

  1. Avoid the client until the next scheduled visit
  2. Promise a full replacement immediately to end the complaint
  3. Explain that the repair was correct and the client must be mistaken
  4. Listen fully, restate the concern, recheck the system readings, and explain the findings Correct answer.

Explanation

Active listening, verification with instrument readings, and a clear explanation address the complaint professionally and protect quality. Dismissing the client or making unauthorized promises escalates the issue and misrepresents the service.

Question 10Basic Competencies (workplace communication, teamwork, safety, quality standards)

Which record is most important to complete immediately after recovering refrigerant from a residential system?

  1. The number of tools returned to the service bag
  2. The model of the technician's vacuum gauge
  3. The amount recovered and the cylinder used, entered in the service and recovery log Correct answer.
  4. The client's preferred appointment time for the next visit

Explanation

Recovery records tie the quantity and cylinder to the job, supporting inventory control and environmental compliance. Appointment and tool details are unrelated to refrigerant accountability.

Question 11Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician is instructed to install a unit in a way that conflicts with the manufacturer's installation manual. What is the appropriate action?

  1. Raise the conflict with the supervisor and follow the manufacturer's requirements Correct answer.
  2. Install as instructed and note the deviation only if a failure occurs later
  3. Follow the verbal instruction because a supervisor outranks a manual
  4. Modify the manual page to match the instruction

Explanation

Manufacturer requirements define safe and warrantable installation, so a conflict must be raised before work proceeds. Following an instruction that contradicts them can void warranty and create a hazard.

Question 12Basic Competencies (workplace communication, teamwork, safety, quality standards)

Which action best reflects the principle of maintaining quality standards during a routine cleaning task on an evaporator coil?

  1. Following the specified cleaning procedure and checking the result against the acceptance criteria Correct answer.
  2. Using any available solvent regardless of the coil material
  3. Skipping the coil rinse because the drain looks clear
  4. Cleaning only the visible front face of the coil to save time

Explanation

Quality means performing the specified procedure and verifying the outcome against defined criteria. Partial cleaning, skipped steps, and unsuitable chemicals produce hidden defects and possible coil damage.

Question 13Basic Competencies (workplace communication, teamwork, safety, quality standards)

A two-person crew must lift a heavy condensing unit onto a mounting frame. Which teamwork practice best reduces injury risk?

  1. Lift quickly with straight legs and a bent back to gain momentum
  2. Carry the unit up a ladder without securing the frame first
  3. Agree on the lift plan and count before lifting, keeping the load close and using leg strength Correct answer.
  4. Have the stronger member lift alone while the other guides the unit

Explanation

A coordinated lift plan with a count, close load, and leg-driven technique distributes the load and reduces musculoskeletal injury. One-person lifting, momentum, and unsecured access all increase risk.

Question 14Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician receives a verbal instruction that contradicts the written work order regarding the refrigerant type to be charged. What is the best course of action?

  1. Charge nothing and leave the job without informing anyone
  2. Charge the refrigerant named in the verbal instruction
  3. Pause and confirm the correct refrigerant with the supervisor before charging Correct answer.
  4. Charge a blend that works for both refrigerants mentioned

Explanation

Conflicting instructions must be resolved before a critical step such as charging, because the wrong refrigerant can damage the system and compromise safety. Blending or guessing is never acceptable, and abandoning the job without notice breaks accountability.

Question 15Basic Competencies (workplace communication, teamwork, safety, quality standards)

A crew is working in an occupied home when the client asks them to hurry because guests are arriving. Which response best balances client relations with safety and quality standards?

  1. Skip the pressure test to save time for the client
  2. Work faster by removing personal protective equipment
  3. Explain the steps that cannot be shortened and give a realistic completion time Correct answer.
  4. Ask the client to leave the room so the crew can work without comment

Explanation

Communicating which steps are non-negotiable and giving a realistic timeline manages expectations without compromising safety or quality. Skipping tests or removing protective equipment trades permanent risk for temporary speed.

Question 16Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician discovers that a co-worker has been venting refrigerant to speed up a recovery. What is the most appropriate professional action?

  1. Stop the practice, remind the co-worker of the required recovery procedure, and report it to the supervisor Correct answer.
  2. Mention it to the client but not to the supervisor
  3. Ignore it because the co-worker is more experienced
  4. Join in so the job finishes sooner

Explanation

Venting refrigerant violates environmental and workplace rules, so the practice should be stopped, corrected, and escalated through supervision. Silence or participation makes the technician complicit in a prohibited act.

Question 17Basic Competencies (workplace communication, teamwork, safety, quality standards)

Which document best supports traceability when a client disputes the quality of a completed repair weeks later?

  1. A verbal summary given to the client at the end of the visit
  2. A signed service report listing the diagnosis, parts replaced, readings, and technician name Correct answer.
  3. The technician's personal notes kept at home
  4. A photo of the unit taken before the visit

Explanation

A signed report with diagnosis, parts, readings, and technician identity provides a verifiable record of what was done and by whom. Personal notes, casual photos, and verbal summaries lack the completeness and acknowledgment needed for traceability.

Question 18Basic Competencies (workplace communication, teamwork, safety, quality standards)

Which of the following best describes the purpose of a toolbox talk before a DomRAC installation job?

  1. To test the refrigerant charge of the unit
  2. To review the day's tasks, hazards, and controls with the crew Correct answer.
  3. To record the client's payment schedule
  4. To decide which technician will drive the service vehicle

Explanation

A toolbox talk is a short pre-work briefing that aligns the crew on tasks, hazards, and controls. Payment, transport, and charge testing are separate matters handled elsewhere.

Question 19Basic Competencies (workplace communication, teamwork, safety, quality standards)

A technician needs to tell a client that a needed part will arrive two days later than promised. Which message best meets professional communication standards?

  1. Blame the supplier without offering a new schedule
  2. Say nothing and hope the client does not notice the delay
  3. Ask a co-worker to deliver the news without any details
  4. Inform the client promptly with the new date and the reason, and confirm the rescheduled visit Correct answer.

Explanation

Prompt, factual notice with a new date and confirmation respects the client and keeps the schedule accurate. Silence, blame without a plan, and vague relayed messages erode trust and create confusion.

Question 20Basic Competencies (workplace communication, teamwork, safety, quality standards)

Which behavior best demonstrates respect for diversity and professional ethics within a DomRAC service team?

  1. Using nicknames based on a teammate's ethnicity during briefings
  2. Giving instructions clearly and treating all teammates fairly regardless of background Correct answer.
  3. Excluding a teammate from the toolbox talk because of language differences
  4. Assigning the dirtiest tasks only to newer members as a tradition

Explanation

Fair, clear treatment of all teammates supports an inclusive workplace and is a basic ethical expectation. Hazing traditions, ethnic nicknames, and exclusion on the basis of language are discriminatory and damage team performance.

Question 21Common Competencies (tools and equipment, measurement, materials handling, documentation)

A domestic refrigeration technician is about to braze a joint on a copper line. Which personal protective equipment is most important for protecting the eyes during this task?

  1. Ordinary reading glasses
  2. A cloth dust mask
  3. Tinted safety goggles with side shields Correct answer.
  4. A face shield worn over contact lenses

Explanation

Brazing produces intense visible and infrared light plus flying flux and hot particles, so impact-rated tinted goggles with side shields protect against both glare and spatter. Ordinary eyewear lacks impact rating and side protection.

Question 22Common Competencies (tools and equipment, measurement, materials handling, documentation)

Before using a manifold gauge set on an R-410A system, what should the technician confirm about the gauge set and hoses?

  1. That the gauge faces are colored red on both sides
  2. That the hoses have been stored at room temperature for a day
  3. That the low-side hose is longer than the high-side hose
  4. That they are rated for the higher system pressure and marked for the refrigerant in use Correct answer.

Explanation

R-410A operates at roughly 1.6 times the pressure of R-22, so gauges, hoses and seals must carry a pressure rating suited to it and be dedicated to that refrigerant to avoid cross-contamination. Hose length, gauge color and storage temperature do not establish pressure safety.

Question 23Common Competencies (tools and equipment, measurement, materials handling, documentation)

Which instrument is the correct choice for checking the superheat of a refrigeration system by reading suction line temperature and suction pressure?

  1. A clamp-on ammeter
  2. A megohmmeter
  3. A digital vacuum gauge
  4. A manifold gauge set with a pipe clamp thermometer Correct answer.

Explanation

Superheat is the difference between the measured suction line temperature and the saturation temperature corresponding to the suction pressure, so a pressure gauge set plus a contact thermometer on the line is required. Vacuum gauges, ammeters and insulation testers measure unrelated quantities.

Question 24Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician records a suction pressure of 60 psig on an R-22 system. Using a pressure-temperature chart, the corresponding saturation temperature is about 34°F. If the suction line temperature is 48°F, what is the superheat?

  1. 14°F Correct answer.
  2. 48°F
  3. 34°F
  4. 18°F

Explanation

Superheat equals suction line temperature minus saturation temperature, so 48°F minus 34°F gives 14°F. The other figures either restate one reading or add the values incorrectly.

Question 25Common Competencies (tools and equipment, measurement, materials handling, documentation)

When measuring the temperature of a bare copper suction line with a contact thermometer, which practice gives the most reliable reading?

  1. Hold the probe loosely near the line in the air stream
  2. Insulate the probe against the pipe after cleaning the contact area Correct answer.
  3. Read the probe immediately after removing it from the toolbox
  4. Place the probe on the liquid line instead

Explanation

A clean contact point and insulation over the probe reduce the influence of ambient air, which otherwise pulls the reading toward room temperature. Loose placement, cold-start readings and the wrong line all introduce error.

Question 26Common Competencies (tools and equipment, measurement, materials handling, documentation)

What is the main reason for using a calibrated torque wrench when tightening flare nuts on refrigerant lines?

  1. To avoid under-tightening leaks and over-tightening that cracks the flare Correct answer.
  2. To measure the refrigerant charge indirectly
  3. To shorten the time spent on the connection
  4. To allow reuse of the old flare nut

Explanation

Flare joints leak when too loose and split or deform when over-tightened, so the manufacturer's torque value is applied with a torque wrench. Speed, part reuse and charge measurement are not the purpose.

Question 27Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician must lift a reciprocating condensing unit weighing about 60 kg from a pallet onto a mounting base. Which approach follows safe materials-handling practice?

  1. Lift it alone with a straight back and twist toward the base
  2. Use a mechanical hoist or two-person team with proper lifting technique Correct answer.
  3. Drag it across the floor to save effort
  4. Roll it on the refrigerant lines for leverage

Explanation

Loads beyond a safe single-person limit should be moved with mechanical assistance or a coordinated team, keeping the back straight and the load close. Twisting, dragging and loading the piping risk injury and equipment damage.

Question 28Common Competencies (tools and equipment, measurement, materials handling, documentation)

Which storage practice best protects refrigerant cylinders in a service shop?

  1. Store them beside the brazing torch set for convenience
  2. Lay them horizontally under a workbench
  3. Store upright, capped and secured in a ventilated area away from heat Correct answer.
  4. Keep them in a sealed closet to prevent theft

Explanation

Cylinders should stand upright with valve caps fitted, be restrained against falling, and be kept in a well-ventilated area away from ignition sources and heat. Horizontal storage, proximity to torches and sealed unventilated spaces create hazards.

Question 29Common Competencies (tools and equipment, measurement, materials handling, documentation)

When nitrogen is used to pressurize a system for a leak test, what regulator feature is essential?

  1. A high-pressure regulator that reduces cylinder pressure to the test pressure Correct answer.
  2. A check valve that blocks all flow
  3. A vacuum gauge on the cylinder outlet
  4. A flowmeter only

Explanation

A nitrogen cylinder delivers very high pressure, so a two-stage or adjustable regulator is needed to bring it down to a safe test pressure. A flowmeter or vacuum gauge does not control downstream pressure.

Question 30Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician needs to evacuate a split air-conditioning system and confirm the required vacuum level is held. Which instrument is designed for this?

  1. A dial thermometer
  2. A refrigerant leak detector
  3. A compound gauge on the manifold
  4. An electronic vacuum gauge (micron gauge) Correct answer.

Explanation

An electronic micron gauge measures deep vacuum accurately in the range needed for dehydration, whereas manifold gauges are not precise below atmospheric pressure. Thermometers and leak detectors serve other purposes.

Question 31Common Competencies (tools and equipment, measurement, materials handling, documentation)

Which unit conversion is correct when a specification states a system charge of 1.5 kilograms?

  1. About 33 pounds
  2. About 3.3 pounds Correct answer.
  3. About 0.68 pounds
  4. About 1.5 pounds

Explanation

One kilogram equals approximately 2.2046 pounds, so 1.5 kg is about 3.3 lb. The other values misplace the decimal or invert the conversion.

Question 32Common Competencies (tools and equipment, measurement, materials handling, documentation)

A service report must record gauge pressure, but the manufacturer's table is in absolute pressure. If the gauge reads 30 psig at sea level, what is the approximate absolute pressure?

  1. About 15 psia
  2. About 45 psia Correct answer.
  3. About 30 psia
  4. About 60 psia

Explanation

Absolute pressure equals gauge pressure plus atmospheric pressure, and standard atmosphere at sea level is about 14.7 psi, so 30 psig is roughly 45 psia. The other options omit or double the atmospheric addition.

Question 33Common Competencies (tools and equipment, measurement, materials handling, documentation)

Which measuring tool is appropriate for checking the diameter of a copper tube to confirm it matches the fitting size?

  1. A vernier caliper or tube-size gauge Correct answer.
  2. A feeler gauge
  3. A steel rule laid across the tube end
  4. A plumb bob

Explanation

A vernier caliper or dedicated tube gauge gives a direct outside-diameter reading that can be matched to nominal tube size. A rule across the end, a feeler gauge and a plumb bob do not measure diameter reliably.

Question 34Common Competencies (tools and equipment, measurement, materials handling, documentation)

In the service documentation for a domestic refrigerator, which entry is the most important to record immediately after recovering refrigerant from a system?

  1. The name of the tool supplier
  2. The room temperature at the start of the shift
  3. The color of the recovery cylinder
  4. The weight or amount of refrigerant recovered and the cylinder used Correct answer.

Explanation

Recovery records must show how much refrigerant was removed and into which container, supporting inventory control and legal reporting. Cylinder color, supplier names and shift temperature do not document the refrigerant movement.

Question 35Common Competencies (tools and equipment, measurement, materials handling, documentation)

A job order lists the model and serial number of the unit to be serviced. Why is this information recorded on the service report?

  1. To determine the ambient humidity
  2. To choose the brazing torch tip size
  3. To identify the exact equipment for warranty, history and parts lookup Correct answer.
  4. To calculate the refrigerant superheat

Explanation

Model and serial numbers tie the work to a specific unit, which is essential for warranty claims, service history and ordering correct parts. They do not drive superheat calculation, humidity or torch selection.

Question 36Common Competencies (tools and equipment, measurement, materials handling, documentation)

When completing a refrigerant handling log, a technician records cylinder tare weight and gross weight. What does the difference between these two values represent?

  1. The weight of refrigerant currently in the cylinder Correct answer.
  2. The cylinder's pressure rating
  3. The age of the cylinder
  4. The moisture content of the refrigerant

Explanation

Gross weight minus tare weight gives the net weight of the contents, which is how refrigerant quantity in a cylinder is tracked. Pressure rating, age and moisture are separate attributes.

Question 37Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician is handed a wiring diagram and a service manual for a window-type air conditioner. Which document is used to trace the electrical path of the compressor circuit?

  1. The refrigerant charge label
  2. The owner's operating instructions
  3. The warranty certificate
  4. The wiring diagram Correct answer.

Explanation

The wiring diagram shows component connections and conductor routing, which is what is needed to trace a circuit. Charge labels, operating instructions and warranty papers do not depict electrical paths.

Question 38Common Competencies (tools and equipment, measurement, materials handling, documentation)

While reading a nameplate on a domestic refrigerator, a technician sees 'R-134a, 120 g'. What does this information specify?

  1. The compressor speed and the voltage
  2. The refrigerant type and the mass of charge Correct answer.
  3. The insulation thickness and the cabinet volume
  4. The refrigerant type and the suction pressure

Explanation

The nameplate charge statement names the refrigerant and gives its mass, which guides charging by weight. It does not state operating pressure, compressor speed, voltage or cabinet dimensions.

Question 39Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician must cut and ream a 3/8-inch copper line before making a flare. Which sequence of tools is correct?

  1. Pipe wrench, then reamer, then vacuum pump
  2. Tube cutter, then reamer, then flaring block and yoke Correct answer.
  3. Hacksaw, then flaring block, then torque wrench
  4. Deburring tool, then manifold gauge, then tube bender

Explanation

A tube cutter produces a square end, the reamer removes the internal burr, and the flaring block with yoke forms the flare. The other sequences either omit deburring or substitute tools that do not perform the step.

Question 40Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician plans to solder a copper joint on a potable-water line that shares a wall penetration with a refrigerant line. Which precaution is most relevant to materials handling and cross-contamination?

  1. Keep refrigerant oils and flux residues from entering the water line and clean the joint afterward Correct answer.
  2. Leave the water line open during brazing to vent pressure
  3. Store the flux in an unlabeled container for speed
  4. Use the same brush for flux and for applying refrigerant oil

Explanation

Separating consumables and cleaning joints prevents flux and oil residues from contaminating the water system. Sharing brushes, leaving lines open and unlabeled containers all increase contamination and misidentification risk.

Question 41Common Competencies (tools and equipment, measurement, materials handling, documentation)

A recovery cylinder is filled to 90 percent of its capacity by weight. Why is this limit observed?

  1. To keep the cylinder label visible
  2. To reduce the cost of the refrigerant
  3. To make the cylinder easier to carry
  4. To leave room for liquid expansion and prevent hydrostatic pressure buildup Correct answer.

Explanation

Liquid refrigerant expands with temperature, so filling to the rated fill limit leaves headspace and prevents dangerous hydrostatic pressure. Handling ease, label visibility and cost are not safety reasons.

Question 42Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician measures 0.5 inch of water column pressure drop across a filter in a duct. Which instrument is designed for this measurement?

  1. An inclined or digital manometer Correct answer.
  2. A hygrometer
  3. A clamp-on ammeter
  4. A compound gauge

Explanation

Small air-pressure differences in ducts are measured with an inclined or digital manometer, which resolves fractions of an inch of water column. Refrigerant gauges, ammeters and hygrometers measure other quantities.

Question 43Common Competencies (tools and equipment, measurement, materials handling, documentation)

During a site visit, a technician finds a leaking refrigerant cylinder valve in the storage area. Which action order best reflects safe handling?

  1. Move the cylinder into the office for closer inspection
  2. Evacuate and ventilate the area, remove ignition sources, then address the cylinder per procedure Correct answer.
  3. Wipe the valve with oil to stop the leak
  4. Seal the room to contain the gas, then continue work

Explanation

Refrigerant vapors displace air and some blends are flammable, so the priority is to ventilate, remove ignition sources and keep people clear before handling the cylinder. Sealing the room, applying oil and moving the cylinder indoors worsen the hazard.

Question 44Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician is preparing a service report after replacing a compressor. Which combination of records best supports a warranty claim?

  1. Only the customer's phone number
  2. Model and serial numbers, measured pressures and temperatures before and after, parts used and technician signature Correct answer.
  3. The ambient temperature on the day of purchase
  4. A photograph of the toolbox

Explanation

A defensible warranty record shows equipment identity, documented before-and-after readings, parts installed and who performed the work. Contact details alone, toolbox photos and purchase-day weather do not substantiate the repair.

Question 45Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician is choosing between a vacuum pump and a recovery machine for a job that requires removing refrigerant before opening the circuit. Which statement correctly matches the tool to the task?

  1. The recovery machine is used only for nitrogen pressure testing
  2. The recovery machine transfers refrigerant to a cylinder; the vacuum pump removes non-condensables and moisture after the circuit is closed Correct answer.
  3. The vacuum pump transfers refrigerant to a cylinder; the recovery machine pulls a deep vacuum
  4. Both tools perform the same function and are interchangeable

Explanation

Recovery moves refrigerant out of the system into a container, while evacuation with a vacuum pump removes air and moisture once the system is sealed. They are distinct operations and cannot substitute for each other.

Question 46Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician is issued a new digital manifold gauge set for R-410A service. Before using it on a job, which check confirms the instrument is fit for the task?

  1. Confirm the gauge body is painted the same colour as the R-410A cylinder
  2. Confirm the gauge display shows ambient temperature when switched on
  3. Confirm the gauge has a longer hose set than the previous analogue unit
  4. Confirm the gauge is rated for R-410A pressure ranges and the calibration certificate or self-test is current Correct answer.

Explanation

A manifold gauge must be rated for the pressures and refrigerant it will see, and its accuracy must be traceable through a current calibration or self-test before field use. Colour coding and hose length are conveniences, not evidence of fitness for duty.

Question 47Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician must record a measured superheat of 8 K in the service report, but the only available thermometer reads in degrees Celsius with 1 °C graduations. Which statement about the record is correct?

  1. The reading cannot be recorded until a Fahrenheit thermometer is borrowed
  2. A temperature difference of 8 K equals 8 °C, so the value is recorded as 8 °C difference Correct answer.
  3. The value should be doubled because two thermometer readings are subtracted
  4. The value must be converted using the 1.8 factor because Kelvin and Celsius differ in size

Explanation

The kelvin and the degree Celsius have the same interval size, so a temperature difference of 8 K is exactly a difference of 8 °C. Only absolute temperatures need the 273.15 offset; differences never require the 1.8 factor.

Question 48Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician is writing the materials list for a job that requires 12 m of 1/4-inch copper tubing, 4 flare nuts, and 2 kg of refrigerant. Which documentation practice keeps the requisition accurate and traceable?

  1. Write the quantities on the refrigerant cylinder label instead of the requisition
  2. List each item with its description, size, quantity and unit of measure, and reference the job order number Correct answer.
  3. Combine all items into one line labelled 'air-conditioning materials' to save space
  4. Record only the total peso value of the materials on the requisition

Explanation

A requisition must identify each item unambiguously by description, size, quantity and unit, and must be linked to the job order so consumption can be traced and reconciled. Lumping items together or recording only cost destroys that traceability.

Question 49Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician needs to measure the wall thickness of a copper tube at a joint to decide whether it is still within specification. Which instrument gives a direct reading of wall thickness?

  1. A steel rule placed against the cut end
  2. A tube micrometer with a ball or curved anvil Correct answer.
  3. A flaring block with the tube clamped in it
  4. A vernier caliper used across the outside diameter

Explanation

Wall thickness is measured with a micrometer whose anvil is shaped to sit against the curved tube wall, giving a direct thickness reading. Outside-diameter calipers, rules and flaring blocks do not measure wall thickness.

Question 50Common Competencies (tools and equipment, measurement, materials handling, documentation)

A technician receives a service manual showing a wiring diagram, a parts list, and a troubleshooting chart for a domestic refrigerator. The unit trips its overload protector shortly after start-up. Which use of these documents is most appropriate for diagnosing the fault?

  1. Use the parts list first to order a compressor, then confirm with the wiring diagram after fitting
  2. Use the wiring diagram only to locate the power cord, and rely on experience for the rest
  3. Use the troubleshooting chart to narrow the symptoms, then the wiring diagram to trace the start circuit and the parts list to identify the replacement component Correct answer.
  4. Use the service manual to record the customer's address and contact details

Explanation

The troubleshooting chart maps symptoms to likely causes, the wiring diagram shows how the start circuit is actually connected so the fault can be traced, and the parts list identifies the exact replacement. This sequence narrows the fault before any part is ordered.